Seamless steel pipe can be classified into the following several kinds because of its different standards:
1. GB/T8162-1999 (the structure is made by seamless steel tube). It is mainly used for the general structure and the mechanical structure. It represents textures (brands) : carbon steel No 20 and No 45; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.
2. GB/T8163-1999 (seamless steel tube is used for transmitting fluid). It is mainly used in engineering and large equipments in pipes conveying fluid. The standard materials (brands) are 20, Q345, etc.
3. GB/T3087-1999 (low and intermediate pressure boiler is made by seamless steel tube). It is mainly used in industrial boiler and boiler of low intermediate pressure fluid pipe. Standard materials are Steel No 10, No 20.
4. GB/T5310-1995 (high pressure boiler is made by seamless steel tube). It is mainly used for high voltage transmission fluid collection box and the pipeline in power plant and high temperature resistant nuclear power plant boiler. Standard materials are 20G, 12Cr1MoVG, 15CrMoG, etc.
5. GB/T5312-1999 (ships are made by seamless steel tube of carbon steel and carbon manganese steel). It is mainly used for Marine boiler and overheating is used the class I and class II pressure tubes, etc. Standard materials are steel grade 360, 410, 460, etc.
6. GB/T1479-2000 (seamless steel tube is used in high pressure chemical fertilizer equipments). It is mainly used for transmitting high-temperature and high-pressure liquid pipeline in fertilizer equipments. Standard materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.
7. GB/T9948-1988 (seamless steel tube is used in oil cracking). It is mainly used in the boiler in oil smelting plants, heat exchangers and pipes conveying fluid. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.
8. GB/T18248-2000 (cylinders are made by seamless steel tube). It is mainly used for making all kinds of gas and hydraulic cylinders. Its represents materials are 37Mn, 34Mn2V, 35CrMo, etc.
9. (GB/T17396-1998 hydraulic prop is made by hot rolled seamless steel tube). It is mainly used for making hydraulic support and cylinder, column, and other hydraulic cylinder, column for coal mining. Its representative materials are 20, 45, 27SiMn, etc.
10. (GB/T3093-1986 diesel engine is made by high-pressure seamless steel tube). High pressure oil pipe is mainly used for diesel injection system. The steel pipe is commonly cold drawn pipe, and its representative material is 20A.
11. GB/T3639-1983 (cold drawn or cold rolled precision seamless steel tube). It mainly used in steel pipes for the mechanical structure, carbon pressure equipment of high precise size and good surface finish. Its representative materials are Steel No 20 and No 45, etc.
12. GB/T3094-1986 (
cold drawn seamless and shaped steel tube). It is mainly used for making all kinds of components and parts; its materials are of high quality carbon structural steel and low alloy steel.
13. GB/T8713-1988 (hydraulic and pneumatic cylinder are made by precision inner diameter seamless steel tube).It is mainly used in the production of hydraulic and pneumatic cylinder are made of precise cold drawn or cold rolled seamless steel tube. Its representative materials are Steel No 20 and No 45, etc.
